Triple-evap autocascade

[REDKEN]

Hi guys!

Ok I need some help on deciding how my phase-change setup is going to be. So, all the help that you can give me will be highly appreciated.
I have been doing lots of reading and many threads and articles. Mostly from 2002-2003 , I'm guessing those were the years were phase change boomed and now it's died out somewhat.
Upps..sorry! Back to the topic.

After some thinking, I have decided that what I what is a triple-evap autocascade with a shutoff valve on one of the arms. That can dissipate the heat of an FX57 and two x800xtpe, of course all extremely overclocked.
So...he barely wants anything,right?:)

Now for the first round of questions:

1- The most obvious first question would have to be. Can it be done?
2- How much HP would the compressor need to have?
3- Can a “regular” sized condensor be used for this? (regular = the kind you see mostly used in Chilly1's,Vapos, Mach's and other custom made)
4- Can a valve be put in one of the capillaries to shutoff cooling to one of the evaporators, to be opened when needed?

I want this to be a good investment for me. So, it has to be as future proof as possible.
Right now I would cool down the CPU and one GPU. But in the future I plan on moving to dual GPU's. That's were the capillary valve comes in. I want to leave one of the arms dormant till its needed, but the system has to be prepared for the load.
And I want to use only one compressor. That's were the autocascade comes in :).

So, what do you guys think?

[bh2k]

If my knowledge serves me right, it should be possible, but very hard since you are controlling the pressure of 3 suction lines. The compressors also would have to be very powerful as well since the cascade is dealing with 3 heat sources instead of one. 1.5-2hp comps probably because the 1st stage would get higher strain from the higher strain on the 2nd stage.

[Epsilon]

A two compressor setup would be much easier though

2x 1/2hp will do the trick when you go with R507 on the 1st stage and Ethane in de 2nd. Ethane is a far easier refridgerant than ethylene. The temps are lower though, but if you were expecting -80c on all three the evaps of the autocascade you are certainly dreaming :). -70c certainly is possible with 2x 1/2hp and R507/Ethane

[gkiing]

A triple evap setup is nearly impossible at best to tune, the only person I know that did one was bowman a few years back. Add an autocascade to the mix and you're in for a big migrane. Most of the people here have not yet perfected the autocascade, and you should get that working before you attempt a triple evap.

[Redwolf]

1) Yes
2) 2hp R404A/507 Ultra low temp, 220V 1phase
3) No... just buy the condensing unit. It comes with the compressor, condensor, etc.
4) If you've got a reciever for each stage.

Now.. lets come back down to reality. Have you ever worked with refrigerants before? Do you have any idea what kind of a head ache a project like this would intale? What evaporator temps are you looking to get?

[REDKEN]

A two compressor setup would be much easier though

2x 1/2hp will do the trick when you go with R507 on the 1st stage and Ethane in de 2nd. Ethane is a far easier refridgerant than ethylene. The temps are lower though, but if you were expecting -80c on all three the evaps of the autocascade you are certainly dreaming :). -70c certainly is possible with 2x 1/2hp and R507/Ethane

Which would be a better option now that i'm contemplating a 2 compressor setup:
1- A triple-evap cascade.
2- A single autocascade for CPU and a Dual-evap autocascade for the two GPU's.

What would be a better setup? and why?

Thanks for your help guys. I'm starting to get pretty exited about going into phase-change :)

[Epsilon]

When using two compressors i'm talking about regular cascades

autocascades and multiple evaps, well, wake up :)
yes, it is possible because it are two separated things. The autocascade will be tuned seperately. But even then, it will be damn hard.

A regular cascade with 3 evaps is more possible. AND would give better temps

edit:

Wait a minute, you will be building this system yourself?

Good luck and see you in 3 years :D

no offence but this is advanced stuff. Only the very experienced builders can pull of this kind of system.

[chilly1]

2-1 hp compressors and PEV's on all three evaps have a 10 Oz recirever on both high and low temp condensers. When unused open the valve all the way and insulate it..

[Redwolf]

Thats a good way of doing it.
Would be the most simple for the most bang.

[kayl]

A triple evap setup is nearly impossible at best to tune, the only person I know that did one was bowman a few years back. Add an autocascade to the mix and you're in for a big migrane. Most of the people here have not yet perfected the autocascade, and you should get that working before you attempt a triple evap.


does anyone know the link to this.

[illmatik]

Man.. I'm just going thru a basic college level hvac course self study style.. This seems like quite an undertaking... I would almost think that a more practical solution would be an autocascade for cpu and traditional cascade for chipset/gpu(s), no?

[REDKEN]

So I take it that a triple-evap cascade will be a better setup than a single autocascade for CPU and a Dual-evap autocascade for the two GPU's,Right?
I theory what kind of teps would be possible?


2-1 hp compressors and PEV's on all three evaps have a 10 Oz recirever on both high and low temp condensers. When unused open the valve all the way and insulate it..
Is this the best way to cool three devises with two compressors? Or is this How a triple-evap cascade should be done?

I guess the better question would be. What is the best way to cool three devices using two 1/2HP compressors? What kind of temps would I see?.

Thanks guys and sorry for all the questions. I'm still learning as you can see, and I'm loving it!:)

[REDKEN]

A two compressor setup would be much easier though

2x 1/2hp will do the trick when you go with R507 on the 1st stage and Ethane in de 2nd. Ethane is a far easier refridgerant than ethylene. The temps are lower though, but if you were expecting -80c on all three the evaps of the autocascade you are certainly dreaming :). -70c certainly is possible with 2x 1/2hp and R507/Ethane
Is this -70c load?
This temp would be nice under load, and it's what I'm looking for right now.

[reject]

opinions are varied on this topic, but i think your gonna have a hard time tuning a autocascade for good load temps, especially since you are a phase change noob.
how about a dual evap single stage for the gfx cards, and then a single stage on cpu. using propane or a propane mix, the cpu could get about -30 (evap -45) loaded and gfx cards could easily be -50 gpu

[REDKEN]

I never did say that I was building it guys:).
Yes, I am a phase-change noob and will have somebody knowledgeable make the system for me. Most probably someone from the forums here.
But before I ask anybody to build me a system I need to know what to ask him for, right? Don't want to bother with too many PM's when I can do my own research and ask the community to get an idea between what I want and what can be done.
So, given the fact that there are no "skills" limitation on building this system. My question still stands:
What is the best way to cool three devices using two 1/2HP compressors? What kind of temps would I see?.

The reason I'm concentrating more on 1/2HP units its because I want to keep my monthly cost to about 10-15 dollars a month. I found this (http://productiveenergy.com/calculator/compressor.asp) site here that calculated the cost for me.


how about a dual evap single stage for the gfx cards, and then a single stage on cpu. using propane or a propane mix, the cpu could get about -30 (evap -45) loaded and gfx cards could easily be -50 gpu
I haven't found much information on how much insulation does the gxf card has to have at for example -50c. Does the regular insulation work? or will I have to do more, like dielectric gease on the pci-e socket and stuff?

I hope you guys can help me out here. I need more opinions.

[Redwolf]

Best you'll see with a set up like that is around -40F using both compressors. One for CPU other for GPUs. So one single, one dual.

How about changing your water cooling set up to a -70F loop temp?

[REDKEN]

Best you'll see with a set up like that is around -40F using both compressors. One for CPU other for GPUs. So one single, one dual.
Why so little?


How about changing your water cooling set up to a -70F loop temp? Are you talking about waterchilling? I looked into that and would have been great for me but it just takes too long to cool down the water. For example: Starting with 20.8c liquid it would take 18:36min to reach -40c.
The way I use my computer I would not like to wait 20min. so I can use it. :p: As for the rest, waterchilling is very good and flexible.

Thanks!

[afireinside]

not sure about autocascades but cascades arent exactly something you can run 24/7. If you somehow manage to make it useable 24/7 you than have to deal with the NOISE, need for large amounts of insulation, and electricity bills.

[Redwolf]

Why not state what you want... rather than guess?

[berkut]

Im working on a dual head autocascade

[REDKEN]

not sure about autocascades but cascades arent exactly something you can run 24/7. If you somehow manage to make it useable 24/7 you than have to deal with the NOISE, need for large amounts of insulation, and electricity bills.
If I were to have two 1/2hp compressors in a cascade setup, why would it cost more that a 1hp single stage? I know that 1hp=745.6w, how many watts does a typical compressor use?

[REDKEN]

Why not state what you want... rather than guess?
I think I did. I want the best way to cool down three devices without costing be an arm and a leg to run every month.
That is why I think that no more than 1hp should cost me about $12 to run a month. That is based on about 2hr a day and 8 on the weekends, also using 745.6w 100% load 85% efficiency, which is more watts than I think any "commonly" used PC compressor uses. I used the calculator I posted above.
I'm just want you guys to help me on this decision. As I said, this will be an investment for me and I have to make an informed decision. Also I want it to last along while.

Thanks for the help you have given me so far.:)

[REDKEN]

cascading 24/7 is very possible..a 3 evap auto cascade is a dream..a 3 evap 2 stage cascade is possible.
:) ok I get it

[gkiing]

cascading 24/7 is very possible..a 3 evap auto cascade is a dream..a 3 evap 2 stage cascade is possible.

What's required for a 24/7 cascade? A really efficient oil separator?

[reject]

are you sure you only use it 2 hours a day in the week? i know i turn it on when i get home form school and leave it on till i got to bed, thats like 7-8 hours
and youll need much more insulation than you think. grease in the slot, id even put it in nearby slots, and under caps both on card and board, cling wrap on card, neoprene... your probly gonna need about 20$ of insulation on each card
and a cascade has 2 compressors, and a massive AC fan, i know my DD is very loud without any muffling, and its only got 1 quiet compressor and a 120mm fan. couldnt hear the tv across the room

[GuGaCoSa]

WOW,I dont think a 3 evaps autocascade can be done properly,with only 1 evap is a PITA to tune,dont wanna see it with 3 heads,with clogging tubes by the dry ice with co2 hehe,I think you should try first a single stage with 2 or 3 evapas,even this is really hard.

[Redwolf]

My point is what temps do you want? Dont believe you ever stated that.
Only Auto-C. That could mean -100C for all we know.

Refrigeration design.....
1) design load
2) design tempature of load
3) components

Why try to skip to step 3?

[saratoga]

What's required for a 24/7 cascade? A really efficient oil separator?

I'm curious too.

[Redwolf]

So whats the plan?
Get what you can get out of a 1hp (something)?

[REDKEN]

are you sure you only use it 2 hours a day in the week? i know i turn it on when i get home form school and leave it on till i got to bed, thats like 7-8 hours
and youll need much more insulation than you think. grease in the slot, id even put it in nearby slots, and under caps both on card and board, cling wrap on card, neoprene... your probly gonna need about 20$ of insulation on each card
and a cascade has 2 compressors, and a massive AC fan, i know my DD is very loud without any muffling, and its only got 1 quiet compressor and a 120mm fan. couldnt hear the tv across the room
I just found out that a common compressor (like the Danfoss NF) runs at about 310w. So, using two for even 5 hours a day 20 on weekends would still be below $20. Which is ok with me:) Remember my first estimate was based on using 745.6w 100% load 85% efficiency.
I work and will be starting school again soon, so I won't be using my PC so much during the week any more:(

I have read articles on how to insulate, but how do you guys test your insulation?


WOW,I don’t think a 3 evaps autocascade can be done properly, with only 1 evap is a PITA to tune,dont wanna see it with 3 heads,with clogging tubes by the dry ice with co2 hehe,I think you should try first a single stage with 2 or 3 evapas,even this is really hard. I gave up on the triple-evap idea. Now I'm looking at one PS unit for my CPU and one "dual-evap" for my GPU's

My point is what temps do you want? Don’t believe you ever stated that.
Only Auto-C. That could mean -100C for all we know. I'm not looking for -100c (for the moment :D). What I want right now is -50 load (or very close to it) on all devices.

So what’s the plan?
Get what you can get out of a 1hp (something)? If using Danfoss compressors get me the temps I want, I'll go with those. If not, something "bigger" has to be used. Anybody know how much HP does the Danfoss unit have?
I found the datasheet here (http://de.refrignet.danfoss.com/TechnicalInfo/Literature/Manuals/06/NF55CLX_R404A-R507_115V_60Hz_09-02_Cf53g122.pdf) but couldn't determine the horsepower.

[Revv23]

sounds to me like it would be more economical for you to have a dual evap single phase unit and then when you get a 2nd video card you can build another unit for that... maybe you could try a triple evap single phase, wouldnt be so easy though.

[Redwolf]

Looks like a 1/3hp lowtemp 115V Danfoss.
Should work great for the CPU. Not sure about 2 GPUs tho.... Say 300W max @ -45C